The present invention describes esters of alkylthioalkanoic acids defined according to the structure: ##STR2## wherein R.sub.1 represents C.sub.3 -C.sub.6 alkenyl or C.sub.1 -C.sub.4 alkyl; R.sub.2 represents C.sub.3 alkyl; C.sub.3 hydroxyalkyl or C.sub.3 alkenyl; N represents 0, 1 or 2 and M represents 0 or 1 and uses thereof in augmenting or enhancing the aroma or taste of foodstuffs.
Artificial flavoring agents for foodstuffs have received increasing attention in recent years. In many areas, such food flavoring agents are preferred over natural flavoring agents at least in part because of the uniform flavor that may be so obtained. For example, natural food flavoring agents such as extracts, essences, concentrates and the like are often subject to wide variation due to changes in the quality, type and treatment of the raw materials. Such variation can be reflected in the end product and results in unreliable flavor characteristics and uncertainty as to consumer acceptance and cost. Additionally, the presence of the natural product in the ultimate food may be undesirable because of increased tendency to spoil. This is particularly troublesome in convenience and snack food usage where such products as dips, soups, chips, prepared dinners, canned foods, sauces, gravies and the like are apt to be stored by the consumer for some time prior to use.
The fundamental problem in preparing artificial flavoring agents is that of achieving as nearly as possible a true flavor reproduction. This generally proves to be a difficult task since the mechanism for flavoring development in many foods is not understood. This is notable in products having roasted, sesame, fresh green, oniony, fruity, Lychee-Nut, garlic, strawberry, juicy, mushroom, scallion-like, cashew, Durian, floral, leafy, leek and meaty (mutton) aroma and taste nuances.
Reproduction of roasted, sesame, fresh green, oniony, fruity, Lychee-Nut, garlic, strawberry, juicy, mushroom, scallion-like, cashew, Durian, floral, leafy, leek and meaty (mutton) aroma and taste nuances has been the subject of a long and continuous search by those engaged in the production of foodstuffs. The severe shortage of food, especially protein foods, in many parts of the world has given rise to the need for utilizing non-meat sources of proteins and making such proteins as palatable as possible. Hence, materials which will closely simulate or exactly reproduce the flavor and aroma of meat, bread, garlic, onion, mushroom, scallion, cashew and roasted nut are required.
Moreover, there are a great many meat containing or meat based foods presently distributed in a preserved form. Examples of these are condensed soups, dry soup mixes, dry meat, freeze dried or lyophilized meats, packaged gravies and the like. While these products contain meat or meat extracts, the aroma, taste and other organoleptic factors are often impaired by the processing operation and it is desirable to supplement or enhance the flavors of these preserved foods with versatile materials which have meat (mutton), roasted, onion, garlic and mushroom aroma and taste nuances.
Food flavors in the alkylthioalkanoic acid ester area are known in the prior art. Thus, various 4-(methylthio)-butanoic acid ester derivatives defined according to the structure: ##STR3## wherein R.sub.3 is lower alkyl are known for augmenting or enhancing the aroma or taste of foodstuffs and other consumable materials as is taught in U.S. Pat. No. 3,870,800 issued on Mar. 11, 1975 (the specification of which is incorporated by reference herein). Thus, in Example XVII at columns 13 and 14 of U.S. Pat. No. 3,870,800 the use of ethyl 4-(methylthio)butyrate is shown to be added to a cooked cheese sauce at the rate of 0.5 ppm. The resulting cheese aroma in heated milk is increased adding notes which are usually present in surface-ripened cheese. It is further stated that the cheese flavor intensity is increased. In Example XVIII, at column 14 of U.S. Pat. 3,870,800, it is further indicated that methyl 4-(methylthio)butyrate when added to a beef broth increases the meat character and enhances the spice note. Methyl 4-(methylthio)butyrate is shown in Example XIX of U.S. Pat. 3,870,800 to enhance the fish flavor of a prepared New England clam chowder when added at the rate of 4 ppm.
German Offenlegungsschrift 3307166 (Cyronak, et al) corresponding to U.S. Application for Patent Ser. No. 360,857 filed on Mar. 22, 1982 relates to a foodstuff comprising an amount of compound having the structure: ##STR4## wherein R and R' independent is either hydrogen or an alkyl group of from 1 to 3 carbon atoms and n is either 0 or 1. It is disclosed in German Offenlegungsschrift 3307166 that when one of the compounds having the structure: ##STR5## is employed in the foodstuff, it enhances the fruity or vegetable flavor of the foodstuff or augments a green pine needle or fruity flavor in the foodstuff.
However, nothing in the prior art discloses the esters of alkylthioalkanoic acids of our invention having the structure: ##STR6## wherein R.sub.1 represents C.sub.3 -C.sub.6 alkenyl or C.sub.1 -C.sub.4 alkyl; R.sub.2 represents C.sub.3 alkyl; C.sub.3 hydroxyalkyl or C.sub.3 alkenyl; N represents 0, 1 or 2 and M represents 0 or 1 and uses thereof in augmenting or enhancing flavors. Furthermore, nothing in the prior art infers or states anything about the unexpected, unobvious and advantageous properties in augmenting or enhancing food flavors of the esters of alkylthioalkanoic acids of our invention.